Power supply device

Abstract

The present application provides a power supply device, comprising: a voltage divider module, a first transformer, a second transformer, and a relay; the voltage divider module is used to connect to a power supply and perform voltage division processing on the power supply voltage provided by the power supply to obtain an input voltage; the relay is connected to the first transformer and the second transformer, and is used to control the operation of the first transformer or the second transformer; the first transformer is connected to the voltage divider module, and is used to perform a first voltage transformation processing on the input voltage in an operating state to obtain a first output voltage; the second transformer is connected to the voltage divider module, and is used to perform a second voltage transformation processing on the input voltage in an operating state to obtain a second output voltage. The present application controls the alternating operation of the first transformer and the second transformer through a relay, and can adaptively adjust the voltage output by the power supply device, thereby improving the safety of the power supply device in supplying power to electrical equipment.

Description

Technical Field

[0001] The present application relates to the technical field of electrical equipment, and in particular to a power extraction device. Background Art

[0002] In a combined primary and secondary pole-mounted circuit breaker, power is supplied to the secondary equipment via a power takeoff device. Specifically, the transformer in the power takeoff device transforms the input voltage and then outputs the transformed voltage to the secondary equipment. According to national standards, a combined primary and secondary pole-mounted circuit breaker must operate continuously at 42 kilovolts (kV) for one minute without causing damage. The rated voltage of the secondary equipment is 27V. With a 42kV input voltage, the voltage output to the secondary equipment, after transformation by the transformer in the power takeoff device, will reach 7.3 times the rated voltage, potentially damaging the secondary equipment. Summary of the Invention

[0003] An embodiment of the present application provides a power supply device that can control the alternating operation of a first transformer and a second transformer through a relay, adaptively adjust the voltage output by the power supply device, and improve the safety of the power supply device in supplying power to electrical equipment.

[0004] The technical solution of the embodiment of the present application is implemented as follows:

[0005] An embodiment of the present application provides a power supply device, comprising:

[0006] A voltage divider module, a first transformer, a second transformer and a relay; the voltage divider module is used to connect to a power supply and perform voltage division processing on the power supply voltage provided by the power supply to obtain an input voltage; the relay is connected to the first transformer and the second transformer and is used to control the operation of the first transformer or the second transformer; the first transformer is connected to the voltage divider module and is used to perform a first voltage transformation processing on the input voltage in an operating state to obtain a first output voltage; the second transformer is connected to the voltage divider module and is used to perform a second voltage transformation processing on the input voltage in an operating state to obtain a second output voltage.

[0007] The above-mentioned power supply device further includes:

[0008] The voltage divider module includes: a first capacitor and a second capacitor; the first capacitor is used to connect to the power supply and perform a first voltage division process on the power supply voltage provided by the power supply; the second capacitor is connected in series with the first capacitor and is used to perform a second voltage division process on the power supply voltage after the first voltage division process to obtain the input voltage.

[0009] The above-mentioned power supply device further includes:

[0010] The first transformer includes a first primary winding and a first secondary winding, and the second transformer includes a second primary winding and a second secondary winding; the first primary winding is connected in parallel with the second capacitor for receiving the input voltage; the first secondary winding is connected to the relay for outputting the first output voltage; the second primary winding is connected in series or in parallel with the first primary winding for receiving the input voltage; the second secondary winding is connected in parallel with the first secondary winding and connected to the relay for outputting the second output voltage.

[0011] The above-mentioned power supply device further includes:

[0012] The number of turns of the first primary winding is greater than the number of turns of the first secondary winding; the number of turns of the second primary winding is greater than the number of turns of the second secondary winding; the number of turns of the first primary winding is the same as the number of turns of the second primary winding; the number of turns of the first secondary winding is greater than the number of turns of the second secondary winding.

[0013] The above-mentioned power supply device further includes:

[0014] The relay includes: an electromagnet, a first switching element, and a second switching element; the electromagnet is connected in parallel with the first secondary winding to control the closing and opening of the first switching element, as well as the closing and opening of the second switching element; the first switching element is connected in series with the first secondary winding to control the operation of the first transformer; the second switching element is connected in series with the second secondary winding to control the operation of the second transformer.

[0015] The above-mentioned power supply device further includes:

[0016] When the first output voltage is less than a preset voltage threshold, the electromagnet controls the first switching element to close and controls the second switching element to open, so that the first transformer operates and the second transformer stops operating; the input voltage is subjected to a first voltage transformation by the first transformer to obtain the first output voltage, and the first output voltage is output to the electrical equipment.

[0017] The above-mentioned power supply device further includes:

[0018] When the first output voltage is greater than or equal to the voltage threshold, the electromagnet controls the first switching element to be disconnected and controls the second switching element to be closed, so that the second transformer operates and the first transformer stops operating; the input voltage is subjected to a second voltage transformation by the second transformer to obtain the second output voltage, and the second output voltage is output to the electrical device.

[0019] The above-mentioned power supply device further includes:

[0020] The ratio between the voltage threshold preset by the relay and the rated voltage of the electrical equipment is a first value; the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a second value; wherein the ratio of the first value to the second value is equal to the ratio of the minimum actual voltage of the electrical equipment to the rated voltage, and the product of the first value and the second value is equal to the ratio of the standard voltage to the operating voltage. The above-mentioned power supply device also includes:

[0021] The ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a third value, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is the third value; wherein, the third value is equal to the square root of the ratio between the standard voltage and the operating voltage.

[0022] The above-mentioned power supply device further includes:

[0023] The ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a fourth value, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a fifth value; wherein, the fourth value is less than the square root of the ratio between the standard voltage and the operating voltage and is greater than 0, and the fifth value is greater than the square root of the ratio between the standard voltage and the operating voltage.

[0024] The embodiments of the present application have the following beneficial effects:

[0025] The power supply device of an embodiment of the present application includes: a voltage divider module, a first transformer, a second transformer, and a relay. The voltage divider module is used to connect to a power supply and divide the power supply voltage provided by the power supply to obtain an input voltage. The relay is connected to the first transformer and the second transformer, and the relay can control the alternating operation of the first and second transformers. Thus, when the voltage transformation capacity of the first transformer can meet the voltage transformation requirements, the first transformer of the power supply device performs a first voltage transformation on the input voltage, and the first output voltage of the first transformer is used as the input voltage of the power consumption device. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the requirements, the relay controls the second transformer to start operation, and the second transformer performs a second voltage transformation on the input voltage, reducing the second output voltage of the second transformer to a voltage range that the power consumption device can withstand. The second output voltage is used as the input voltage of the power consumption device to prevent the power consumption device from burning. Thus, by controlling the alternating operation of the first and second transformers through the relay, the present application can adaptively adjust the output voltage of the power supply device, thereby improving the safety of the power supply device in supplying power to the power consumption device. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1It is a schematic diagram of the circuit structure of a power taking device in the related art;

[0027] Figure 2 This is a schematic diagram of an optional circuit structure of the power extraction device provided in an embodiment of the present application;

[0028] Figure 3 This is another optional circuit structure diagram of the power extraction device provided in the embodiment of the present application;

[0029] Figure 4 This is a schematic diagram of the circuit structure of the power taking device provided in an embodiment of the present application when the first transformer is in operation;

[0030] Figure 5 This is a schematic diagram of the circuit structure of the power taking device provided in an embodiment of the present application when the second transformer is in operation. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] In the following description, reference is made to “some embodiments”, which describes a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0033] In the following description, the terms "first\second" involved are merely used to distinguish similar objects and do not represent a specific ordering of the objects. It is understandable that "first\second" can be interchanged with a specific order or sequence where permitted, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0034] Unless otherwise defined, all technical and scientific terms used in the embodiments of the present application have the same meanings as those commonly understood by those skilled in the art. The terms used in the embodiments of the present application are only for the purpose of describing the embodiments of the present application and are not intended to limit the present application.

[0035] Before further describing the embodiments of the present application in detail, the nouns and terms involved in the embodiments of the present application are explained. The nouns and terms involved in the embodiments of the present application are subject to the following interpretations.

[0036] 1) Primary and secondary integrated pole-mounted circuit breaker: A pole-mounted switchgear that combines distribution automation technology. "Primary and secondary integration" refers to the design that integrates primary equipment (main circuit equipment, such as circuit breakers) and secondary equipment (auxiliary equipment such as control, protection, and monitoring) into one.

[0037] 2) Power extraction device: A device that can extract energy from a specific environment and convert it into usable electrical energy, typically used to power various monitoring devices, sensors, or remote communication equipment. The power extraction device in this application is the power extraction device in a combined primary and secondary pole-mounted circuit breaker set. It is used to provide power to secondary equipment, capable of extracting energy from the primary system to power secondary equipment such as protective relays, communication modules, and automation devices.

[0038] 3) Transformer: A stationary electrical device used to change the magnitude of an alternating current (AC) voltage, either increasing or decreasing it as needed. The transformer operates on the principle of electromagnetic induction: when AC current passes through a primary coil (main coil), it generates a voltage in the secondary coil (secondary coil).

[0039] 4) Rated voltage: The voltage value specified when the equipment or system is designed, indicating the voltage that the equipment should withstand under normal operating conditions.

[0040] 5) Minimum operating voltage: The lowest voltage value at which a device or electronic component can start normally and continue to work. It is one of the device design parameters, ensuring that the device can operate stably above this voltage value without performance degradation or failure to start due to low voltage.

[0041] 6) KA AC relay: A commonly used electromagnetic relay that uses electromagnetic attraction to control the on / off state of a circuit. "KA" indicates a model.

[0042] 7) High-voltage capacitor: A type of capacitor whose main feature is the ability to withstand higher voltages. Usually, its rated voltage is above 1kV. It is used for power factor compensation, voltage stabilization and harmonic filtering in high-voltage environments to improve the operating efficiency and stability of the power system.

[0043] 8) Low-voltage capacitors: usually refers to power capacitors with a rated voltage ranging from 400 volts (V) to 6kV, which can provide capacitive reactive power to compensate for the reactive power caused by inductive loads (such as motors, transformers, etc.), thereby improving the power factor of the system and reducing the transmission of reactive power.

[0044] It should be noted that the low-voltage capacitor and high-voltage capacitor involved in the embodiments of this application are two relative concepts. Specifically, the power extraction device in this application includes at least a first capacitor and a second capacitor, wherein the first capacitor is connected to the high-voltage terminal and carries a relatively high voltage, and the second capacitor carries a relatively low voltage. For ease of explanation, in the embodiments of this application, the high-voltage capacitor is referred to as the first capacitor, and the low-voltage capacitor is referred to as the second capacitor.

[0045] In the related art, the power supply device in the integrated primary and secondary pole mounted circuit breaker is only a transformer. Figure 1 , Figure 1 This is a schematic diagram of the circuit structure of a power tapping device in the related art. The positive terminal of high-voltage capacitor 101 is connected to the power supply, while the negative terminal is connected to the positive terminal of low-voltage capacitor 102, connecting the high-voltage capacitor 101 and the low-voltage capacitor 102 in series. The negative terminal of low-voltage capacitor 102 is grounded. Inductor 103 is connected in parallel with low-voltage capacitor 102. Transformer 104 includes a primary winding 1041 and a secondary winding 1042. Primary winding 1041 is connected in series with inductor 103, while secondary winding 1042 is used to connect to other devices. Typically, the power supply output voltage is 5.7 kV, meaning the input voltage of the power tapping device is 5.7 kV. After voltage transformation by transformer 104, the power tapping device can output a voltage of 27 V (the rated voltage of the electrical equipment) and deliver it to the secondary equipment. According to national standards, integrated primary and secondary pole-mounted circuit breakers must operate continuously at 42 kV for one minute without causing damage. Therefore, the input voltage of the power taking device needs to be gradually increased from 5.7kV to 42kV. When the input voltage increases to 42kV, the output voltage of the transformer 104 will increase to 7.3 times the rated voltage of the secondary equipment (i.e. 27V), which far exceeds the rated voltage of the secondary equipment and can easily burn the secondary equipment.

[0046] Based on the above-mentioned problems existing in the related art, an embodiment of the present application provides a power supply device, which can perform a first voltage transformation on the input voltage through the first transformer of the power supply device when the voltage transformation capacity of the first transformer meets the voltage transformation demand, and use the first output voltage of the first transformer as the input voltage of the electrical equipment. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the voltage transformation demand, the second transformer is controlled to be put into operation through the relay, and the input voltage is subjected to a second voltage transformation through the second transformer, so that the second output voltage output by the second transformer is reduced to within the voltage range that the electrical equipment can withstand, and the second output voltage is used as the input voltage of the electrical equipment to avoid burning of the electrical equipment. In this way, the embodiment of the present application controls the alternating operation of the first transformer and the second transformer through the relay, and can adaptively adjust the voltage output by the power supply device, thereby improving the safety of the power supply device in supplying power to the electrical equipment.

[0047] See also Figure 2 , Figure 2 This is an optional circuit structure diagram of the power supply device provided in the embodiment of the present application. Figure 2 The circuit structure shown is explained.

[0048] In some embodiments, the power supply device includes a voltage divider module 201, a first transformer 202, a second transformer 203 and a relay 204; the voltage divider module 201 is used to connect to a power supply and perform voltage division processing on the power supply voltage provided by the power supply to obtain an input voltage; the relay 204 is connected to the first transformer 202 and the second transformer 203, and is used to control the operation of the first transformer 202 or the second transformer 203; the first transformer 202 is connected to the voltage divider module 201, and is used to perform a first voltage transformation processing on the input voltage in an operating state to obtain a first output voltage; the second transformer 203 is connected to the voltage divider module 201, and is used to perform a second voltage transformation processing on the input voltage in an operating state to obtain a second output voltage.

[0049] Here, relay 204 is a KA AC relay, used to control the alternating operation of first transformer 202 and second transformer 203 based on the magnitude of the first output voltage. First transformer 202 and second transformer 203 are capable of performing varying degrees of voltage transformation on the input voltage, including stepping up or stepping down the input voltage. The first and second output voltages serve as input voltages for the power-consuming device. For example, in the case of a power-taking device applied to a primary-secondary integrated pole-mounted circuit breaker, the power-consuming device is the secondary device. In actual application, the power supply outputs the power supply voltage to voltage divider module 201, which divides the power supply voltage to obtain the input voltage and outputs it to either first transformer 202 or second transformer 203. Relay 204 controls the operation of either first transformer 202 or second transformer 203 based on the magnitude of the input voltage. The first transformer 202 then performs a first voltage transformation on the input voltage to obtain a first output voltage, which is then output to the secondary device; alternatively, the second transformer 203 performs a second voltage transformation on the input voltage to obtain a second output voltage, which is then output to the secondary device.

[0050] In an embodiment of the present application, the alternating operation of the first transformer and the second transformer is achieved by controlling the relay. When the voltage transformation capacity of the first transformer can meet the voltage transformation demand, the first transformer of the power taking device performs a first voltage transformation on the input voltage, and the first output voltage of the first transformer is used as the input voltage of the power consumption device. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the demand, the second transformer is controlled to start operation through the relay, and the second transformer performs a second voltage transformation on the input voltage, so that the second output voltage of the second transformer is reduced to a voltage range that the power consumption device can withstand, and the second output voltage is used as the input voltage of the power consumption device, thereby avoiding the burning of the power consumption device and improving the safety of the power taking device supplying power to the power consumption device.

[0051] In some embodiments, see Figure 2 The voltage divider module 201 includes a first capacitor 11 and a second capacitor 12. The first capacitor 11 is connected to the power supply and is used to perform a first voltage division process on the power supply voltage provided by the power supply; the second capacitor 12 is connected in series with the first capacitor 11 and is used to perform a second voltage division process on the power supply voltage after the first voltage division process to obtain the input voltage.

[0052] Here, the first capacitor 11 is a high-voltage capacitor, and the second capacitor 12 is a low-voltage capacitor. Low-voltage capacitors and high-voltage capacitors are two relative concepts. "High voltage" refers to the part with a higher voltage level in the power system, usually above 1KV, and "low voltage" refers to the part with a lower voltage level in the power system, usually below 1KV. The positive pole of the first capacitor 11 is connected to the power supply, and the negative pole is connected to the second capacitor 12. The positive pole of the second capacitor 12 is connected to the negative pole of the first capacitor 11, and the negative pole of the second capacitor 12 is grounded. The first capacitor 11 performs a first voltage division process on the power supply voltage provided by the power supply and outputs it to the second capacitor 12. The second capacitor 12 receives the power supply voltage after the first voltage division process output by the first capacitor 11, and performs a second voltage division process to obtain the input voltage.

[0053] In the embodiment of the present application, the series combination of high-voltage capacitors and low-voltage capacitors can improve the energy storage capacity, voltage regulation capability, system protection capability and operating range of the power-taking device, thereby improving the overall performance and reliability of the system when the power-taking device is applied to the system.

[0054] In some embodiments, see Figure 2The first transformer 202 includes a first primary winding 21 and a first secondary winding 22, and the second transformer 203 includes a second primary winding 31 and a second secondary winding 32; the first primary winding 21 is connected in parallel with the second capacitor 12 for receiving an input voltage; the first secondary winding 22 is connected to the relay 204 for outputting a first output voltage; the second primary winding 31 is connected in parallel with the first primary winding 21 for receiving an input voltage; the second secondary winding 32 is connected in parallel with the first secondary winding 22 and connected to the relay 204 for outputting a second output voltage.

[0055] Here, the winding is the core component of the transformer that enables power transmission. It is typically wound with copper or aluminum wire. The primary winding is connected to the input power source and receives power from the external power source. The secondary winding is connected to the load and outputs the power converted by the transformer. The first and second primary windings 21 and 31 serve as input terminals, connected to the power source. The second primary winding 31 and second secondary winding 32 serve as output terminals, connected to the load (i.e., the electrical equipment). In the example of a power extraction device applied to a primary-secondary integrated pole-mounted circuit breaker, the load is the secondary equipment. The second primary winding 31 is connected in parallel with the first primary winding 21 to ensure that the input voltages of the first transformer 202 and the second transformer 203 are equal. Relay 204 is connected to the first and second secondary windings 22 and 32 and controls whether the circuits between the first and second transformers 202 and 203 and the electrical equipment are connected, thereby controlling whether the first and second transformers 202 and 203 enter operation or enter an unloaded state.

[0056] In some possible implementations, see Figure 3 , Figure 3 This is another optional circuit structure diagram of the power supply device provided in an embodiment of the present application. Here, the first primary winding 301 is connected in series with the second primary winding 302. Here, if the specifications and parameters of the two transformers are consistent and the coil process meets the standards, the first transformer and the second transformer can also be connected in parallel by connecting the primary windings of the first transformer and the second transformer in series and connecting the secondary windings of the first transformer and the second transformer in parallel.

[0057] In an embodiment of the present application, the first transformer and the second transformer are connected in parallel by connecting the primary windings of the two transformers in series or in parallel and the secondary windings in parallel. In this way, the input voltages of the primary windings of the two transformers are ensured to be equal, which facilitates the alternating operation of the first transformer and the second transformer.

[0058] In some embodiments, the number of turns of the first primary winding is greater than the number of turns of the first secondary winding, the number of turns of the second primary winding is greater than the number of turns of the second secondary winding, the number of turns of the first primary winding is the same as the number of turns of the second primary winding, and the number of turns of the first secondary winding is greater than the number of turns of the second secondary winding.

[0059] Here, the number of turns of the primary winding refers to the number of turns of conductors wound in the coil on the primary side (primary) of the transformer, and the number of turns of the secondary winding refers to the number of turns of conductors wound in the coil on the secondary side (secondary) of the transformer. The ratio of the number of turns of the primary winding to the number of turns of the secondary winding determines the ratio between the input voltage and the output voltage. If the number of turns of the primary winding is greater than the number of turns of the secondary winding, then the ratio of the number of turns of the primary winding to the number of turns of the secondary winding is greater than 1, which means that the ratio between the input voltage and the output voltage is greater than 1, indicating that the transformer is a step-down transformer. In this embodiment of the present application, since the number of turns of the first primary winding is greater than the number of turns of the first secondary winding, and the number of turns of the second primary winding is greater than the number of turns of the second secondary winding, both the first transformer and the second transformer are step-down transformers. For step-down transformers, if the number of turns of the primary winding is the same, the fewer the turns of the secondary winding, the greater the transformer's step-down capability. Since the number of turns of the first secondary winding is greater than the number of turns of the second secondary winding, the second transformer's step-down capability is greater than that of the first transformer. For example, the first transformer can step down a voltage of 9V to 6V, and the second transformer can step down a voltage of 9V to 2V.

[0060] In this embodiment of the present application, the number of turns of the secondary winding is controlled to ensure that the second transformer has a greater voltage-stepping capability than the first transformer. Thus, when the first transformer's voltage-transforming capability meets the required voltage transformation, the first transformer, with its lower voltage-stepping capability, performs a first voltage-transforming operation on the input voltage to produce a first output voltage. When the input voltage increases and the first transformer's voltage-transforming capability is insufficient, the second transformer performs a second voltage-stepping operation, with a stronger voltage-stepping effect, on the input voltage. This further reduces the output voltage of the power supply device and improves the safety of the power supply device in supplying power to the electrical equipment.

[0061] In some embodiments, see Figure 2 The relay 204 includes: an electromagnet 43, a first switching element 41, and a second switching element 42; the electromagnet is connected in parallel with the first secondary winding 22, for controlling the closing and opening of the first switching element 41, and the closing and opening of the second switching element 42; the first switching element 41 is connected in series with the first secondary winding 22, for controlling the operation of the first transformer 202; the second switching element 42 is connected in series with the second secondary winding 32, for controlling the operation of the second transformer 203.

[0062] Here, the first switching element 41 and the second switching element 42 are two independent switches, each with an independent armature, and the position of the armature controls the closing and opening of the switches. It should be noted that in the embodiment of the present application, only one of the first switching element 41 and the second switching element 42 can be in the closed state. That is, when the first switching element 41 is closed, the second switching element 42 is open; or, when the first switching element 41 is open, the second switching element 42 is closed. The electromagnet 43 can convert electrical energy into mechanical energy. When current passes through the coil of the electromagnet 43, it generates a magnetic field around it. This magnetic field attracts the armatures in the first and second switching elements 41, 42, causing the armatures to change their positions, thereby controlling the closing or opening of the first and second switching elements 41, 42. Closing the first switching element 41 connects the circuit of the first transformer 202, thereby putting the first transformer 202 into operation; closing the second switching element 42 connects the circuit of the second transformer 203, thereby putting the second transformer 203 into operation.

[0063] In an embodiment of the present application, the relay includes an electromagnet, a first switching element, and a second switching element. The electromagnet automatically controls the first switching element and the second switching element based on a received first input voltage, thereby controlling the operation of the first transformer or the second transformer. Therefore, the relay can adaptively switch the operation of the corresponding transformer based on the first input voltage, thereby improving the flexibility of the power supply device.

[0064] In some embodiments, see Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of the power extraction device provided in an embodiment of the present application when the first transformer is operating. When the first output voltage is less than a preset voltage threshold, electromagnet 403 controls first switch element 401 to close and second switch element 402 to open, causing first transformer 404 to operate and second transformer 405 to stop operating. First transformer 404 then performs a first voltage transformation on the input voltage to generate a first output voltage, which is then output to the power-consuming device.

[0065] Here, the preset voltage threshold is also referred to as the relay's breaking voltage or disconnecting voltage. The preset voltage threshold enables the electromagnet 403 to generate sufficient suction force to attract the armature. When the first output voltage is less than the preset voltage threshold, the electromagnet's magnetic force is unable to attract the armature to change position, and the armature is in the default position. At this time, the first switch element 401 is closed, and the second switch element 402 is open. When the first output voltage is greater than the preset voltage threshold, the electromagnet's magnetic force increases, and the armature changes position due to the magnetic attraction. At this time, the first switch element 401 is open, and the second switch element 402 is closed. In other words, when the first output voltage is less than the preset voltage threshold, the armature control switch of the first switch element 401 is closed, the circuit between the first transformer and the electrical device is connected, and the first transformer is put into operation. The input voltage is subjected to the first voltage transformation process to obtain the first output voltage, which is output to the electrical device. The armature control switch of the second switch element 402 is opened, and the circuit between the second transformer and the electrical device is disconnected, entering a no-load state and ceasing operation.

[0066] In this embodiment of the present application, the electromagnet in the relay can control the closing and opening of the first switching element and the second switching element based on the first output voltage of the first transformer, thereby controlling the operation of the first transformer or the second transformer. When the first output voltage is less than a preset voltage threshold, the first transformer's voltage reduction capacity meets the required requirements, the first transformer operates, and the power extraction device normally supplies power to the power-consuming device, ensuring stable operation of the power extraction device.

[0067] In some embodiments, see Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of the power extraction device provided in an embodiment of the present application when the second transformer is in operation. When the first output voltage is greater than or equal to the voltage threshold, electromagnet 503 controls first switch element 501 to open and second switch element 502 to close, causing second transformer 505 to operate and first transformer 504 to stop operating. Second transformer 505 then performs a second transformation on the input voltage to generate a second output voltage, which is then delivered to the power-consuming device.

[0068] Here, when the first output voltage exceeds a preset voltage threshold, the armature of the first switching element 501 is attracted by the magnetic force of the electromagnet 503 and moves to a position that opens the first switching element 501. The armature of the second switching element 502 is attracted by the magnetic force of the electromagnet 503 and moves to a position that closes the second switching element 502. Since the first switching element 501 is connected in series with the first secondary winding of the first transformer, opening the first switching element 501 disconnects the circuit between the first secondary winding and the electrical device, and the first transformer ceases operation. Since the second switching element 502 is connected in series with the second secondary winding of the second transformer, closing the second switching element 502 connects the circuit between the second secondary winding and the electrical device. The second transformer performs a second transformation on the input voltage, generating a second output voltage, which is then output to the electrical device.

[0069] It should be noted that the first switching element 501 and the second switching element 502 have a reset function. That is, when the first output voltage drops from greater than a preset voltage threshold to less than the preset voltage threshold, the armatures in the first switching element 501 and the second switching element 502 return to their default state, i.e., the first switching element 501 closes again and the second switching element 502 opens again. Specifically, the armature reset function can be achieved by adding a spring to the armature portion.

[0070] In an embodiment of the present application, when the first output voltage is greater than a preset voltage threshold, the voltage-stepping capability of the first transformer is insufficient to meet the demand. Continuing to power the electrical device with the first output voltage output by the first transformer may cause the electrical device to overvoltage and burn out. Therefore, a second transformer is controlled by a relay. Since the second transformer has a greater voltage-stepping capability than the first transformer, the second transformer can reduce the voltage output by the power supply device to a voltage range that the electrical device can withstand, preventing the electrical device from burning out and thereby improving the safety of the power supply device supplying power to the electrical device.

[0071] In some embodiments, the ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a first value; the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a second value; wherein, the ratio of the first value to the second value is equal to the ratio of the minimum actual voltage of the electrical equipment to the rated voltage, and the product of the first value and the second value is equal to the ratio of the standard voltage to the operating voltage.

[0072] Here, standard voltage refers to the voltage value that the equipment must withstand according to national standards. Operating voltage refers to the input voltage of the power supply device when the first output voltage equals the rated voltage of the electrical equipment. That is, after the operating voltage is transformed by the first transformer, the first output voltage output is the rated voltage of the electrical equipment. The rated voltage of the electrical equipment refers to the standard operating voltage specified during the equipment's design, i.e., the voltage value the equipment should be connected to for optimal performance and safety. The minimum actual voltage of the electrical equipment refers to the lowest voltage level at which the equipment can operate normally. The rated voltage and minimum actual voltage are determined by the equipment manufacturer based on the equipment's electrical characteristics and operating environment, and are typically indicated on the equipment's nameplate or manual. It should be noted that during the actual setup process, the calculated results of multiple data often include multiple digits after the decimal point. To facilitate the parameter setting of each component, an approximation of the actual calculated result is usually selected as the final calculated result. For example, if the actual calculated result is 8.35967, its approximate value of 8.4 is used as the final calculated result.

[0073] For example, consider a power-taking device used in a combined primary and secondary pole-mounted circuit breaker. According to national standards, the standard voltage is 42 kV. The rated voltage of the power-consuming equipment, or secondary equipment, is 27 V, and the minimum actual voltage is 85% of the rated voltage. When the power-taking device input voltage is 5.7 kV, the first output voltage of the first transformer is 27 V, so the operating voltage is 5.7 kV. Let X represent the first value, Y represent the second value, N1 represent the number of turns of the first secondary winding of the first transformer, and N2 represent the number of turns of the second secondary winding of the second transformer. Therefore, the relay's preset voltage threshold is X × 27 V, N1 / N2 = Y, X / Y = 0.85, and XY = 42 kV / 5.7 kV ≈ 7.3. Calculation yields X = 2.49 and Y = 2.93. In other words, the relay's preset voltage threshold is 2.49 times the rated voltage of the power-consuming equipment, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is 2.93. In this way, the voltage of the electrical equipment is equal from the moment before the first switching element is disconnected to the period when the input voltage reaches 42kV and lasts for one minute; at the moment when the first switching element is disconnected and the second switching element is closed, the voltage of the electrical equipment drops instantaneously from 2.49 times the rated voltage to 0.85 times the rated voltage; therefore, the minimum voltage of the electrical equipment is 85% of the rated voltage, and the maximum voltage is 2.49 times the rated voltage.

[0074] Through the embodiments of the present application, the maximum voltage that the electrical equipment needs to withstand can be reduced to the minimum value while meeting the minimum actual voltage of the electrical equipment, thereby protecting the electrical equipment and improving the safety of the power supply device to the electrical equipment.

[0075] In some embodiments, the ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a third value, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a third value; wherein the third value is equal to the square root of the ratio between the standard voltage and the operating voltage.

[0076] It's also important to note that in actual setup, the calculation results for multiple data often include multiple digits after the decimal point. To facilitate parameter setting for each component, approximations of the actual calculation results are used as the final calculation results. For example, consider a power tap device used in a combined primary and secondary pole-mounted circuit breaker. According to national standards, the standard voltage is 42kV. The power-consuming equipment is secondary equipment, with a rated voltage of 27V and a minimum actual voltage of 85% of the rated voltage. When the power tap device input voltage is 5.7kV, the first output voltage of the first transformer is 27V, meaning the operating voltage is 5.7kV. Therefore, the third value is equal to the square root of 42kV / 27V, which is approximately 2.7. Therefore, the preset voltage threshold for the relay is 2.7 × 27V, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is 2.7. Thus, during actual operation, the minimum voltage of the power-consuming equipment does not fall below the rated voltage, and the maximum withstand voltage is 2.7 times the rated voltage.

[0077] Through the embodiments of the present application, the maximum voltage that the electrical equipment needs to withstand can be minimized while ensuring that the minimum voltage of the electrical equipment is not lower than the rated voltage, thereby improving the safety of the power supply device to the electrical equipment.

[0078] In some embodiments, the ratio between the preset voltage threshold of the relay and the rated voltage of the electrical equipment is a fourth value, and the ratio of the number of turns between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a fifth value; wherein the fourth value is less than the square root of the ratio between the standard voltage and the operating voltage, and is greater than 0, and the fifth value is greater than the square root of the ratio between the standard voltage and the rated voltage.

[0079] Here, the fourth value is less than the square root of the ratio between the standard voltage and the operating voltage, and the difference between the fourth value and the square root of the ratio between the standard voltage and the operating voltage is typically no more than 1. The fifth value is greater than the square root of the ratio between the standard voltage and the rated voltage, and the difference between the fifth value and the square root of the ratio between the standard voltage and the operating voltage is also typically no more than 1. It should also be noted that in actual configuration, the calculation results of multiple data often include multiple digits after the decimal point. To facilitate parameter setting of various components, an approximation of the actual calculation results is used as the final calculation result. For example, a power tap device used in a primary and secondary integrated pole-mounted circuit breaker requires a standard voltage of 42 kV according to national standards. The power-consuming device is a secondary device with a rated voltage of 27 V, and the minimum actual voltage is 85% of the rated voltage. When the input voltage of the power tap device is 5.7 kV, the first output voltage of the first transformer is 27 V, which means the operating voltage is 5.7 kV. Therefore, the square root of the ratio between the standard voltage and the operating voltage is the square root of 42 kV / 27 V, which is approximately equal to 2.7. Therefore, 0 < the fourth value < 2.7, so it can be set to 2.5; the fifth value is greater than 2.7 and can be set to 3. Thus, before the first switching element opens, the voltage across the electrical device is 2.4999... times the rated voltage. At the moment the first switching element opens and the second switching element closes, the voltage across the electrical device is 2.5 / 3 times the rated voltage, slightly lower than the rated voltage. While the power supply voltage remains at 42 kV for one minute, the voltage across the electrical device is 2.4 times the rated voltage.

[0080] In an embodiment of the present application, when the voltage of the electrical equipment is slightly lower than the rated voltage for a period of time, the maximum voltage that the electrical equipment needs to withstand can be reduced as much as possible, thereby improving the safety of the power supply device to the electrical equipment.

[0081] In summary, in an embodiment of the present application, when the voltage transformation capacity of the first transformer can meet the voltage transformation demand, the first transformer of the power taking device performs a first voltage transformation on the input voltage, and the first output voltage output by the first transformer is used as the input voltage of the electrical equipment. When the input voltage increases and the voltage transformation capacity of the first transformer cannot meet the demand, the second transformer is controlled to be put into operation through a relay, and the second transformer performs a second voltage transformation on the input voltage, so that the second output voltage output by the second transformer is reduced to a voltage range that the electrical equipment can withstand, and the second output voltage is used as the input voltage of the electrical equipment to avoid burning of the electrical equipment. In this way, the present application controls the alternating operation of the first transformer and the second transformer through a relay, and can adaptively adjust the voltage output by the power taking device, thereby improving the safety of the power taking device in supplying power to the electrical equipment.

[0082] The above description is merely an embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, and improvements made within the spirit and scope of the present application are included in the scope of protection of the present application.

Claims

1. A power supply device, characterized in that: The device includes: a voltage dividing module, a first transformer, a second transformer and a relay; the voltage reduction capability of the second transformer is greater than that of the first transformer; The voltage dividing module is used to connect to a power supply and perform voltage dividing processing on the power supply voltage provided by the power supply to obtain an input voltage; The relay is connected to the first transformer and the second transformer, and is used to control the first transformer to operate and the second transformer to stop operating when the first output voltage of the first transformer is less than a preset voltage threshold; or, when the first output voltage is greater than or equal to the voltage threshold, the relay is used to control the second transformer to operate and the first transformer to stop operating; The first transformer is connected to the voltage dividing module and is used to perform a first voltage transformation on the input voltage in an operating state to obtain the first output voltage. The first output voltage within the voltage range that the electrical device can withstand is used as the input voltage of the electrical device; The second transformer is connected to the voltage divider module and is used to perform a second voltage transformation on the input voltage in an operating state to obtain a second output voltage, the second output voltage being used as the input voltage of the electrical device, and the second output voltage being within a voltage range that the electrical device can withstand; The ratio of the voltage threshold to the rated voltage of the electrical device is a first value; the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a second value; the ratio of the first value to the second value is equal to the ratio of the minimum actual voltage of the electrical device to the rated voltage, and the product of the first value and the second value is equal to the ratio of the standard voltage to the operating voltage; or, the ratio of the voltage threshold to the rated voltage of the electrical device is a third value, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is the third value; the third value is equal to the square root of the ratio between the standard voltage and the operating voltage; or, the ratio of the voltage threshold to the rated voltage of the electrical device is a fourth value, and the turns ratio between the first secondary winding of the first transformer and the second secondary winding of the second transformer is a fifth value; the fourth value is less than the square root of the ratio between the standard voltage and the operating voltage and greater than 0, and the fifth value is greater than the square root of the ratio between the standard voltage and the operating voltage.

2. The power extraction device according to claim 1, characterized in that: The voltage dividing module includes: a first capacitor and a second capacitor; The first capacitor is used to connect to the power supply and perform a first voltage division process on the power supply voltage provided by the power supply; The second capacitor is connected in series with the first capacitor and is used to perform a second voltage division process on the power supply voltage after the first voltage division process to obtain the input voltage.

3. The power extraction device according to claim 2, characterized in that: The first transformer further includes a first primary winding, and the second transformer further includes a second primary winding; The first primary winding is connected in parallel with the second capacitor and is configured to receive the input voltage; The first secondary winding is connected to the relay and is used to output the first output voltage; The second primary winding is connected in series or in parallel with the first primary winding, and is configured to receive the input voltage; The second secondary winding is connected in parallel with the first secondary winding and is connected to the relay for outputting the second output voltage.

4. The power extraction device according to claim 3, characterized in that: The number of turns of the first primary winding is greater than the number of turns of the first secondary winding; The number of turns of the second primary winding is greater than the number of turns of the second secondary winding; The number of turns of the first primary winding is the same as the number of turns of the second primary winding; The number of turns of the first secondary winding is greater than the number of turns of the second secondary winding.

5. The power extraction device according to claim 3, characterized in that: The relay comprises: an electromagnet, a first switching element and a second switching element; The electromagnet is connected in parallel with the first secondary winding and is used to control the closing and opening of the first switching element and the closing and opening of the second switching element; The first switching element is connected in series with the first secondary winding, and is used to control the operation of the first transformer; The second switching element is connected in series with the second secondary winding and is used to control the operation of the second transformer.

6. The power extraction device according to claim 5, characterized in that: When the first output voltage is less than the voltage threshold, the electromagnet controls the first switching element to close and controls the second switching element to open, so that the first transformer operates and the second transformer stops operating; The first transformer performs a first voltage transformation on the input voltage to obtain the first output voltage, and outputs the first output voltage to the electrical device.

7. The power extraction device according to claim 6, characterized in that: When the first output voltage is greater than or equal to the voltage threshold, the electromagnet controls the first switching element to be disconnected and controls the second switching element to be closed, so that the second transformer operates and the first transformer stops operating; The second transformer performs a second transformation on the input voltage to obtain the second output voltage, and outputs the second output voltage to the electrical device.

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